Adjustable ladder jack



Jan.. 9, 1923.: 1,441,847.. J. R. GOODWIN.

ADJUSTABLE LADDER JACK. FILED APR. 6. 1922.

strength, are of substantial Ysshape, the upper parts thereof diverging for a distance preferably sufficient to cause them to bridge two of the rungs of the ladder' 2, of which a portion is shown. The legs terminate at their upper ends in hooks 3 which are adapted to hook over a rung of the ladder. The divergence of the upper parts of the legs l is such that the hooks 3 are located well towards the stiles of the ladder and consequently the gripping points of the jack are soseparated that tendency to tilt or wobble is minimized. rlhe divergent parts of the legs l are connected by a cross brace lof Strap'inetal which is riveted to them at its ends as shown at 5. The cross brace et insures rigidity of the divergent part of the legs in relation to eachother. This cross brace is provided with struck-up or bent ears 6 and in order not to weaken the cross brace, 'these ears are formed on the upper part of the cross brace which is, therefore, wider at itscenter than at its ends.

The lower part of the legs l extend in the forni of a stem, parallel to each other, for a distance adapting them to bridge two of the rungsof the ladder. lnterposed between the straight parts of the legs l is a ratchet plate 7 which is of stiff sheet metal to insure rigidity and strength. Rivets 8 permanently fasten the ratchet plate 7 to, and between,

they straight portions of the legs l and rig idly connect the said straight portions together. `The location of the ratchet plate T between the straight parts of the legs l and riveting it to the legs, strongly reinforces the stem of the legs so that there is no possibility of buckling and, beside that. no possibility of accidental detachment of the ratchety plate or of its becoming bent. rllhis is of importance because the safety of a jack of this class is no greater than the` safety of the adjustable connection between the supporting members and the leg. Furthermore, it will be seen that the ratchet plate is disposed between two of the rungs of the ladder so that the weight of the stein and the ratchet plate have to support, is distributed between two rungs of the ladder. rlhe ratchet plate 7 is provided with relatively long or deep notches 9 which extend parallel, or substantially so, to the stem of the leg and the mouths 10 are at an abrupt angle to the length of the notches 9. ln consequence, the hooks ll lare long and ksubstantially parallel to the length of the stem of thelegs. Thisconstruction insures against accidental detachment of the lower bearing bar or brace which is shown at l2 and has a decided advantage over lateral opening or merely inclined slots.

The upper bearing bar 13 and the lower bearing bar or brace l2 are both of duplex ccnstructiombeing made of steel bars riveted together at 14, thus insuring against lateral spring or buckling. The upper bearing bar 13 is provided with divergent extremities l5 at its inner end, these heilig pivoted on a long rivet pin or bolt lo whose ends are riveted down on the ears o. ".lho extremities l5 lie inside the ears (l and close to them so that the possibility of spreading is prevented and the double pivot thus pio vided minimizes any twisting or torsional action of the bearing bar 13.

The outer end of the bearing bar lll is spread as at 17 and receives the hook-shapml welded end 'i8 of the lower lgiearing bar l2 which is pivoted thereto on a rivet lil. ,l'hc hooked-shaped end 1S engages the plank :2O shown in dotted lines, and prevents it from slipping off of the bearing bar l?) when the jack is in the position. shown in Figure l.

The lower end of the lower bearing bar l2 is spread apart as shown at l ,so as to straddle not only the ratchet plate T but also 'the parallel webs of 1die stein of the legs. This overlapping of the legs by the ends :2l prevents any possibility of displacement o1' the bearing bar A bolt 22 extends l'roin one part to the other of the fork or end lY and is riveted or headed down against the outer faces of the nieinbers ol" said lork .so 'that there is no possibility of detmhinent. rthis bolt 22 .is of a size adapting it to vasilv yet snugly enter the mouths lil :ind lo lil snugly and easily in the slots 9.

ln Figure l l have shown the manner lu which thel jack is used on the outer face of a ladder as, might be the case. when they painter or carpenter is supported by thc up per partof the ladder und :is ilar down thereon as he can conveniently reach thrwall ot the building.

ln Figure f2 the jack is shown ou the inside of the ladder, that is. between the ladder and the wall of the buildingas would be necessary when working on lower pars of; the wall in order to permit the painter or carpenter to easily reach the wall. 'lhe construction of my iai-lc enables it lo be r f moved and re-hung in its reversed position` as shown in Figure without the necessity of readjusting the lower bearing bu r l2. lh that connection, .it will be observed that the depths and arrangement of the. slots 9 and their mouths l0. render it impossible l'or the bolt Q2 to bcconie accidentally disengaged from the ratchet bar 7.

lhat I claim is:

l. A, ladder jack comprising a doubhl les: whose upper parts are arranged in spaced relationship and are provided with hooks to engage a rung of a ladder and whose lower parts extend closely parallel in the form of stein, a ratchet plate located lwtweon. and secured to the said lower parts and forming a part ol the stem aforesaid. :in upper bearing bar pivotcil to the upper parts of the leg, and a lower bearing bnr pi voted CII Lll)

intiem p l to the upper bearing bar and having means for engaging the teeth of the ratchet plete.

2. A. ladder jaclr comprising a double leg` whose upper parts are arranged in spaced relationship and are provided with hooks to engage a rung` oij' the ladder and whose lower parts extend closely parallel in the torni oit a stern, a ratchet plate located between, and secured to, the said lower parts end forming a part ot the Stein aforesaid, a cross brace connecting the upper parts of the leg, an upper bearing bar having,` parts narl'airg'ecl in spaced relationship to each other 'which are pivoted to 'the cross brace, and a lowerI bearing` bar pivoted to the upper bearing bar and having a iorlred shaped end provided with a bolt lor cngaging the teeth olf the ratchet plate.

l ladder jack comprising a double legwhose upper parts diverge and are provided with hooks to engage a rung ot a ladder and whose lower parte extend parallelin tlie :lorni olf a. stein, a ratchet plate located between, and secured to the inenibers ot the stern aitoreeaid, a cross brace connecting the divergent upper parte ot the leg, said cross brace having separated. lugs creare, an upper l'iearnp,` bar provided with divergent parte at its inner end which are pivotelly connected to the lugs or ears and a lower bearingbar pivoted to the upper bearing bar and having rneans for engaging the ratchet plate.

el. A ladder ack comprising` a double leg whose upper part has divergent sections provided with booke to engage a rung o a ladder and whose lower part has parallel sections secured together, a cross brace connecting the divergent upper parts oit the leg together, said cross brace being provided with separated ears, an upper bearing bar having divergent niien'ibers at its inner end which are pivoted to the ears aforesaid, and a lower bearing member pivoted to the upper bearing' nieinber and provided with lneans for eliecting` locked engagement with the stein or the legs.

:5. ladder acl; conoprising, a double leg the ineinbers ol' which diverge at their upper parte and are prov'ded with hoolrs for engaging a rung ol a ladder and whose lower part-s entend parallel in the torni or' a stern, a ratchet plate located between the inelnbers of said stein and secured to tliein, a cross brace connecting the divergent upper parts or the leg` together, seid cross brace being provided with separated. lugs which are bent up tliere'liroin, en upper dupleir bearingbar composed et rneinbers secured together which diverge at their inner ends and are disposed adjacent the lugs or the cross brace, a pivot bolt connecting eaid divergent ends to the lugs, the outer end of the upper hearing bar having its parte spread, a lower duplex bearing bar having one end received between and pivoted to said spread ends or the upper bearingI bar and extending thereabove to Serve es plank retainer, the other end ol the lower beariiwv bar being spread and provided with a cross pin or bolt adapted to engage the teeth oit the ratchet plate, said lower end oit the lower bearingbar straddling the stein oit the leg.

6. il ladder `iaclr having a leg provided with means ifo-r its attachment to a ladder and provided with stein comprising closely related parallel ports, a ratchet plate located between and connected to the stein and forining a part oilz said stein, eaid ratchet plate having slots entendi substantially pare allel to the stein end provided with entrance mouths disposed at en abrupt angle to said slots, an upper bearing` bar pivoted to the leg', and a lower bcaring1 bar connected to the upper bearing bar and provided with means to enter the Slots aforesaid.

ln testimony whereof l alix rnv signature.

JAMES lil-@Ullllllll 

